str1="hello world"
str2='hello world'
str3='''hello 
world'''
print(str1)
print(str2)
print(str3)
#print('hel/'lo world)
print('123---{0}---{1}---{2}'.format(4,5,6))
str1='hello'
print(f'123---{str1}')

for i in range(0,101,2):
    print("==========开始下载==========")
    if i ==100:
        print("下载完成")
    else:
        str4="*" * (i//2) +"."*((100-i)//2)
        print(f'{i}%[{str4}]')
